The present invention relates to electrolysis and for example utilisation of fuel cell technologies in order to generate hydrogen as a fuel for other uses.
Electrolysis apparatus is known for a number of applications and it is proposed to use water electrolysis as a simple and clean technology for hydrogen production. Electrolysis is the reverse process to fuel oxidation in fuel cells. A schematic of the process is illustrated in FIG. 1. In an electrolysis process steam is dis-associated on a cathode with formation of hydrogen molecules. In solid oxide cells the cathode reaction is as follows:H2O+2e−=H2+O2−
Oxygen ions migrate through the electrolyte forming oxygen molecules on the anode surface with the release of electrons.O2−=½O2+2e−
The overall steam electrolysis reaction is then as follows:H2O+H2+½O2 
In the above circumstances it will be understood that an electrical power source is required to draw electrons from the anode to the cathode overcoming the electrochemical reaction potential.
Although commercial water electrolysis is available at low temperatures through use of known technology the efficiency of operation for these electrolysers is relatively low. Use of high temperature fuel cell technology is inhibited by the necessity for such high temperature fuel cells to operate at temperatures in excess of 800° C. and typically in a range 800° C.-1000° C. In such circumstances it is necessary to use specific heaters which diminish effectiveness and practicability of such approaches.
Currently the most developed technology with regard to hydrogen production is related to steam re-forming. In this process a fossil fuel source is utilised and this contributes significantly to CO2 emissions. Water electrolysis is proposed as a “green house gas free” hydrogen production technology allowing utilisation of non fossil fuel electricity sources such as nuclear or renewable electrical power sources. Unfortunately there is a significant disadvantage with current hydrogen production via water electrolysis in that, as indicated above, there is a relatively low efficiency. Such low efficiency necessitates the use of a relatively high electricity consumption rate rendering the costs of the hydrogen produced by water electrolysis as too expensive for commercial viability relative to that currently produced through steam re-forming. It will also be understood that the equipment cost for current water electrolysers is high again significantly contributing to making water electrolysis the more expensive option for hydrogen production when compared to steam re-forming of natural gas or other hydro carbons.